PTFE - Polytetrafluoroethylene
A Fluoropolymer used mainly for its excellent chemical resistance.
It has poor mechanical features. The strain, even under low weight, makes
it very suitable as a gasket material.
FEATURES
- chemical: a typical fluoropolymer with very high chemical resistance
- mechanical: the mechanical features such as tensile stress and compressive
strength are poor. Notably the bearing strain is very low
- very good resistance to low and high temperatures up to 260° C
as well as to UV rays
- low flammability
- low friction coefficient
- colour: natural
WEAK POINT
Poor mechanical properties. The strain is very high, even simply under
the weight of the piece.
APPLICATION
- chemical: very high chemical resistance to alkali
and acids is the main feature of the fluoropolymers. PTFE is used for
parts in the petrochemical and chemical industries
- food contact: physiologically inert it is approved
for use in contact with food by some standards, whilst in some countries
this use is questioned
- electrical: very good dielectric, self-extinguishing
and weather stability properties make it suitable for this field
- mechanical: the low friction coefficient makes it
suitable for bearings, provided that they work under low charge
The graph shows that PVDF has better mechanical features than PTFE,
together with an economical advantage thanks to its lower gravity.
A: ball identation hardness
B: compressive strength
C: gravity
Grey =PTFE
Yellow = PVDF